Improvement in optical telegraphs



i UNITED STATES 'PATENT OFFICE.

.WILLIAM O. BRIDGES, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN OPTICAL TELEGRAPHS.

Specification forming part of Letters Patent No. $4,127, dated January14, 1862.

To a/ZZ whom it may concern/.-

Be it known that I, WILLIAM C. BRIDGES, of Philadelphia, Pennsylvania,have invented an Instrument for Transmitting Messages; and I do herebydeclare the following to be a full, clear, and eXact description of thesaine, reference being had to the accompanying drawings, and to theletters of reference marked thereon.

My invention consists of ya tube With a lens, and one or more adjustablemirrors arranged, substantially as explained hereinafter, in combinationwith the devices hereinafter described, or their equivalents, forobscuring and exposing the lens, (the latter being illuminated by therays of the sun reiieoted from the mirrors,) or for movingdifferently-colored plates of glass to the front of and away from thelens, so that on observing the latter from a distance its exposure andobscuration or the different colors seen Will be the means of informingthe observer of the nature of the messages transmitted by the operator.

In order to enable others to make and use my invention, I will noWproceed to describe its construction and operation.

On reference to the accompanying drawings, Which form a part of thisspecification, Figure l is a side view of my instrument for transmittingmessages; Fig. 2, a plan View; Fig. 3, an end view looking'in thedirection of the arroW, Fig. 2; and Fig. 4f, a diagram illustrating amodiiication of part of the instrument.

Similar letters refer to similar parts throughout the several views.

A is the base of the instrument, and to this base is attached a tube B,at the rear of which is secured a lens.

To a bracket a on the base is hinged a lever having two arms O and D, onthe outer end of the former of which is a disk d of a diameter as largeas or somewhat larger than the tube B, one end of a spiral spring bbeing connected to the short arm D of the lever, and the other end to apin c secured to the base, and the tendency of this spring being toretain the disk in the elevated position (shown in Fig. 3) from whichpoint it cannot be raised owing to the arm D bearing against a pinprojecting from the bracket a.

On the long arm C of the lever is a projecting plate e ot' properdimensions for receiving the finger of the operator. In front of thislever and its disk d is another disk E so hinged to the base that it canbe elevated at right angles to the same or4 depressed so as to be incontact with the base, as shown by dotted lines, Fig. 2, this diskhaving in its upper edge a notch d corresponding with a notch in a anged at the rear of the tube B, and these notches being so situated that aline a: drawn from the bottom of one notch to that of the other shall beparallel With a line drawn through the center of the tube.

At the rear ot' the tube is a frame to which is hung a circular mirrorF, this frame being so connected to the base A as to be readily turnedthereon, and the mirror being so hung to the frame that it may be movedto any desired angle. A similar mirror G hung to a similar frame may beconnected to the base at the point shown in Fig. 2, or at any otherpoint which may be the most advantageous positjon for the mirror toreceive the direct rays of the sun.

It should be understood that in using the above-described instrument fortransmitting messages it has in the iirst instance to be so adjustedthat the tube may be directed accurately to the point Where the observerwho has to receive the messages is situated, the lens of the tube beingdirectly Within the line of the observers vision. In order to adjust theinstrument to this position, the disk E is iirst raised to the verticalposition shown in Fig. 1, after which the operator, looking to- Ward thenotch in the tlange of the tube B, adjusts the instrument tosuchaposition that the point to which he desires to direct theinstrument, the bottom of the notch on the disk E, and the bottom of thenotch in the iiange shall all be in the same linexof vision.

It Will be understood that in order to facilitate the adjustment of theinstrument it should be attached to a tripod byfmeans of aball-and-socket joint and other appliances similar to those used inconnection With theodolites and other like instruments.

When messages have to be delivered from a great distance, a telescopeshould be connected to the instrument, care being taken that thetelescope is placed parallel with the tube B. In this case the notch indisk E is dispensed with, the adjustment o f the instru# ment beingregulated by the telescope.

The position of the mirrors F and G will depend upon the direction ofthe rays of light from the sun in respect to the position of theinstrument, the mirror G being so adjusted as to receive the direct rayswhich are reilected onto the mirror F, and thence directed onto thelens, which becomes so brilliantly illuminated as to be plainly visiblefrom a distance of twenty-tive miles with the aid of a telescope. v Y

In adjusting the mirror G the focus of the lens illuminated by the lightreflected from the mirror should coincide with a small hole in theelevated disk E, a line drawn through this hole and through the centerofthe tube being parallel with the line drawn from the notch of the diskto the notch of the iiange. If care is not taken to thus adjust themirror G, it will not be fully illuminated.

In some instances the mirror G may be dispensed with, as when theinstrument is so situated that the rays of the sun are received directlyby the mirror F.

In order lo impart greater brilliancy to the lens, a concave instead ofaplain mirror may be used at the rear of the tube, as seen in Fig. 4,the rays from this mirror being concentrated in the lens. y

The messages are delivered by the movements of the disk d, which maybedepressed so as to cover the end of the tube B or be allowed to rise bythe action of the spring b to the position shown in Fig. 3, when the endof the tube is exposed. This obscuring and eX- posing of the illuminatedlens will be clearly seen by the observer either by the naked eye if thedistance be short, or by the aid of a telescope if the distance be long.The operator may move the disk d precisely in the same manner as thoughhe handled the signal-key of an ordinary Morse telegraphing-instrument,and the observer who has to interpret the signals must be guided by thelength of time during which the lens remains obscured and by therapidity of the movements of the disk precisely asl he would be guidedby the ticks of a telegraph instrument. In some cases it may beadvisable to discard the Morse alphabet and to make use of a secretsystem v of signals predetermined by the operators. A

` the messages being guided by the colors presented.

When the instrument has to be used d uring the night, a lamp may be soplaced between the concave mirror and the lens that the rays of lightwill be reflected by the mirror onto the lens, thereby brilliantlyilluminating the latter.

I wish it to be understood that I do not desire to claim, broadly,transmitting messages between distant points by exposing and obscuring aluminous or illuminated object, but that I limit my claim to and desireto secure Letters Patent for- The tube B with its lens and one or moreadjustable mirrors arranged substantially as described, in combinationwith the device herein described or any equivalent to the same forobscuring or exposing the lens or moving diEerently-colored plates ofglass to the front of and away from the lens, as set forth, for thepurpose specified.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

W. C. BRIDGES.

